A cell line derived from mouse epidermis has been established and characterized in our laboratory. The cell line is aneuploid, nontumorigenic, anchorage dependent and dependent on epidermal growth factor (EGF) for proliferation. It has been further designated as epithelial by morphology and biochemical markers such as keratin production. Infection of these cells with several different sarcoma viruses results in morphological change as well as a release from dependence on EGF. Detailed analyses of these virally transformed epithelial cells is currently in progress.